Disposable absorbent articles are well known in the art. Disposable absorbent articles are used to absorb and retain urine and fecal material. A particularly desired feature of disposable absorbent articles is the capability to minimize the task of cleaning of fecal material which is present on the wearer's skin after the soiled disposable absorbent article is removed from the wearer. In order to achieve this end, and to minimize epidermal contact and the associated irritation caused by the fecal material, attempts have been made to confine the fecal material to limited portions of the disposable absorbent article.
References in the prior art disclose a cavity or cutout in the absorbent core to receive the fecal material. The fecal material passes through the topsheet and is received by the material removed from or otherwise displaced from the absorbent core (such as through compression). However, these references suffer from the drawback that a cavity in the absorbent core or a removal of material from the absorbent core decreases its absorbent capacity. The cavity is limited in volume by the size of the absorbent core. Examples of such teachings include U.S. Pat. No. 2,043,325 issued Jun. 9, 1936 to Jackson, Jr.; U.S. Pat. No. 4,731,065 issued Mar. 15, 1988 to Yamada; U.S. Pat. No. 4,834,737 issued May 30, 1989 to Khan; and U.S. Pat. No. 5,062,840 issued Nov. 5, 1991 to Holt et al.
One attempt to minimize the task of cleaning of fecal material from the skin of the wearer is to provide a void space in the disposable absorbent article to receive the fecal material and to isolate it from the skin of the wearer. Typically, the void space is intermediate the topsheet which contacts the skin of the wearer and the absorbent core which absorbs fluid excretions, such as urine. In this arrangement, the topsheet may have an aperture or other passageway which communicates the fecal material into the void space.
Many of these references also disclose various arrangements for providing elastic extensibility to the topsheet relative to the aperture therethrough and the absorbent core. Examples of such teachings include U.S. Pat. No. 4,662,877 issued May 5, 1987 to Williams; commonly assigned U.S. Pat. No. 4,892,536 issued Jan. 9, 1990 to DesMarais et al.; and commonly assigned U.S. Pat. No. 4,990,147 issued Feb. 5, 1991 to Freeland. However, these references suffer from the drawback that the void space for receiving fecal material typically does not remain open when the wearer is in a sitting position or after the first loading has occurred.
To overcome this problem, other references teach adding a spacer to the disposable absorbent article. The spacer may be transversely oriented, generally horse-shoe shaped, or may comprise longitudinally oriented parallel or divergent members. Examples of such references include European Patent Application 0,355,740 A2 published Feb. 28, 1990 in the name of Enloe; UK Patent Application GB 2,074,875 A published Nov. 11, 1981 in the name of Edwards; French Patent Application 2,561,078 published Sep. 20, 1985 in the name of Lefebvre; U.S. Pat. No. 4,382,443 issued May 10, 1983 to Shafer et al.; and U.S. Pat. No. 4,560,380 issued Dec. 24, 1985 to Tharel.
Spacers generally have a planar undeformed configuration. The spacer thickness controls the maximum void space height that can be maintained in the absorbent article. A minimum thickness is necessary to maintain a void space sufficient to receive the fecal material. Spacers are flexurally loaded, or bent, about one or more axes as the spacers are forced to conform to the wearer's anatomy or to deform in response to the wearer's movements.
Known spacers suffer from the drawback that they exhibit flexural rigidity, or resistance to bending or torsion when flexurally loaded. Flexural rigidity reduces a spacer's ability to conform to curvature caused by the wearer's anatomy or to deform in response to the wearer's movements. Spacers which exhibit too much flexural rigidity are undesirable in that they can appear bulky in the absorbent article, and can cause discomfort to the wearer. However, flexural rigidity generally increases with thickness, so that increased spacer thickness results in a more bulky appearance and cause more discomfort to the wearer. Thus, conventional spacers undesirably provide increased void space height at the expense of increased spacer flexural rigidity.
Additionally, known spacers exhibit an elastic flexural resilience. When flexurally deformed, such as by bending, a known spacer will develop internal restoring forces that tend to restore the spacer to its original, or undeformed, shape. These restoring forces can be transmitted to the wearer through the structure of the disposable article, and cause the wearer discomfort or cause improper fit.
Accordingly, it is an object of this invention to provide a spacer which is capable of maintaining a minimum spacer thickness and minimum void space height under compressive loading. It is also an object of this invention to provide a spacer that exhibits relatively little flexural rigidity. It is a further object of this invention to provide a spacer that deforms plastically, rather than elastically, in response to flexural loading about any axis, so that the spacer does not develop restoring forces in response to flexural loading. Yet another object of this invention is to provide a spacer having a number of discrete elements enclosed in an outer cover, wherein each discrete element is capable of motion relative to the other discrete elements enclosed in the outer cover in response to flexural loading of the spacer.